A data amount managed by a company keeps on increasing according to the development of the information society in recent years. On the other hand, for a reduction in management cost of an IT system and the like, an increasing number of general companies adopt a form of not owning an IT system and leasing the IT system from a specialty company which manages and provides the IT system. According to the increase, data managed by the companies are being aggregated in the IT system owned by the specialty company which manages and provides the IT system. In order to make it possible to accumulate the enormous data aggregated in this way, an increase in the size of a storage system included in the IT system steadily advances.
According to the increase in the size of the storage system, the number of objects treated by storage management software for managing the storage system (e.g., the number of volumes provided by a storage apparatus) also increases. As a result of such an increase in the number of objects, a problem occurs in that a maximum number of objects assumed by the storage management software at a design stage is exceeded, a long time is required for acquisition of configuration information necessary for management (e.g., information concerning volumes seen on a host computer and correspondence information between volumes provided by a storage computer and physical storage areas), or it takes time to process information search or the like on the storage management software according to the increase in the number of objects and operation response falls.
In order to solve such a problem, for example, Patent Literature 1 proposes to adopt a configuration in which plural instances of the storage management software having equivalent functions (hereinafter also referred to as “management software instances” or “member instances” or simply referred to as “instances”) are arranged, volumes in the host computer and the storage apparatus, which are management targets, are distributed to each of the instances, and the volumes are managed among the instances in cooperation with one another.